An antimicrobial agent is defined as a substance which kills or inhibits the growth of microbial cells. There are two general types of antimicrobial agents: one that kills the microbe is called a microbiocide and one that stops the growth of microbes called a microbiostat. Antimicrobial agents play a vital role in areas such as health care, hospitals, food packaging and storage, water purification, dental care, and household sanitation. Finishing with antimicrobial agents protects the user of a textile material against microbes related to aesthetic, hygienic or medical problems and protects the textile material itself against biodeterioration from mold, mildew and rot-producing fungi. Today there is substantial market for antimicrobial textiles and is increasing rapidly due to consumer awareness and demand for hygienic clothing and active-wear. In 2000, worldwide production of antimicrobial textiles was 100,000 tons and 30,000 tons in Western Europe. Production increased more than 15% a year from 2001 to 2005 in Western Europe.
There are three different means by which these finishing agents work, namely 1) controlled release mechanism, 2) the regeneration principle, and 3) the barrier or blocking action. In the first mechanism, the textile material is finished with a leachable type of antimicrobial agent which is consumed over a period of time. This type of finishing agents loses effectiveness after a few laundry washes. Another problem associated with this type of finishing agent is that microbes can develop strains that are resistant to the finish and can cause cytotoxicity. Current examples of leachable type of finishing agents are silver ions, triclosan, and polyhexamethylene biguanides (PHMB). In the regeneration principle, the finish must be reactivated by some additional step after use. For antimicrobial halamine finished fabrics the reactivation can be done with chlorine bleach. The residual chlorine odor is a problem with this finish. In the barrier mechanism, the fabric can be finished with an inert physical barrier coating material or surface coatings which can kill microbes on contact. However, present solutions have not produced satisfactory solutions, and there is a need to provide alternative solutions.